Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

Follow-up testing is done to determine how well diet and medications are controlling high cholesterol.

Screening for children is less agreed upon:

Some experts recommend only screening children with risk factors, such as a family history of high cholesterol or early heart disease (a history of heart attacks before age 55 in men, and before age 65 in women).

Some experts recommend screening all children, but according to the U.S. Preventive Services Task Force, there is not enough evidence to recommend for or against cholesterol screening in children.

Normal Values

The ideal values are different for people without coronary artery disease or other risk factors than for those with known coronary artery disease, diabetes, or high blood pressure. The desired values in adults are:

LDL: 70 - 130 mg/dL (lower numbers are desired)

HDL: greater than 40 - 60 mg/dL (higher numbers are desired)

Total cholesterol: less than 200 mg/dL (lower numbers are desired)

Triglycerides: 10 - 150 mg/dL (lower numbers are desired)

VLDL: 2 - 38 mg/dL

Talk to your health care provider about the ideal levels in children.

Note: mg/dL = milligrams per deciliter

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

Abnormal values may be a sign that you are at increased risk for atherosclerosis and related disorders, including:

Heart disease

Kidney disease

Poor blood supply to the legs

Stroke

What the risks are

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

Excessive bleeding

Fainting or feeling light-headed

Hematoma (blood accumulating under the skin)

Infection (a slight risk any time the skin is broken)

References

Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Executive summary of the third report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III). JAMA. 2001;285:2486-2497. Updated 2004.

Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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